// internal sending function. not a RAMFUNC.
bool intMfSniffSend() {
int pckSize = 0;
int pckLen = BigBuf_get_traceLen();
int pckNum = 0;
uint8_t *trace = BigBuf_get_addr();
FpgaDisableSscDma();
while (pckLen > 0) {
pckSize = MIN(USB_CMD_DATA_SIZE, pckLen);
LED_B_ON();
cmd_send(CMD_ACK, 1, BigBuf_get_traceLen(), pckSize, trace + BigBuf_get_traceLen() - pckLen, pckSize);
LED_B_OFF();
pckLen -= pckSize;
pckNum++;
}
LED_B_ON();
cmd_send(CMD_ACK,2,0,0,0,0);
LED_B_OFF();
clear_trace();
return TRUE;
}
static void uncompress_data_section(void)
{
z_stream data_section;
next_free_memory = BigBuf_get_addr();
// initialize zstream structure
data_section.next_in = (uint8_t *) &__data_src_start__;
data_section.avail_in = &__data_end__ - &__data_start__; // uncompressed size. Wrong but doesn't matter.
data_section.next_out = (uint8_t *) &__data_start__;
data_section.avail_out = &__data_end__ - &__data_start__; // uncompressed size. Correct.
data_section.zalloc = &inflate_malloc;
data_section.zfree = &inflate_free;
data_section.opaque = NULL;
// initialize zlib for inflate
inflateInit2(&data_section, 15);
// uncompress data segment to RAM
inflate(&data_section, Z_FINISH);
// save the size of the compressed data section
common_area.arg1 = data_section.total_in;
}
static void init_tag() {
// configure FPGA
FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR
| FPGA_HF_SIMULATOR_MODULATE_212K);
SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
// configure SSC with defaults
FpgaSetupSsc();
// first pull output to low to prevent glitches then re-claim GPIO_SSC_DOUT
LOW(GPIO_SSC_DOUT);
AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;
// reserve a cardmem, meaning we can use the tracelog function in bigbuff easier.
legic_mem = BigBuf_get_addr();
// init crc calculator
crc_init(&legic_crc, 4, 0x19 >> 1, 0x05, 0);
// start 212kHz timer (running from SSP Clock)
StartCountSspClk();
}
/**
* Does the sample acquisition. If threshold is specified, the actual sampling
* is not commenced until the threshold has been reached.
* This method implements decimation and quantization in order to
* be able to provide longer sample traces.
* Uses the following global settings:
* @param decimation - how much should the signal be decimated. A decimation of N means we keep 1 in N samples, etc.
* @param bits_per_sample - bits per sample. Max 8, min 1 bit per sample.
* @param averaging If set to true, decimation will use averaging, so that if e.g. decimation is 3, the sample
* value that will be used is the average value of the three samples.
* @param trigger_threshold - a threshold. The sampling won't commence until this threshold has been reached. Set
* to -1 to ignore threshold.
* @param silent - is true, now outputs are made. If false, dbprints the status
* @return the number of bits occupied by the samples.
*/
uint32_t DoAcquisition(uint8_t decimation, uint32_t bits_per_sample, bool averaging, int trigger_threshold,bool silent)
{
//bigbuf, to hold the aquired raw data signal
uint8_t *dest = BigBuf_get_addr();
uint16_t bufsize = BigBuf_max_traceLen();
BigBuf_Clear_ext(false);
if(bits_per_sample < 1) bits_per_sample = 1;
if(bits_per_sample > 8) bits_per_sample = 8;
if(decimation < 1) decimation = 1;
// Use a bit stream to handle the output
BitstreamOut data = { dest , 0, 0};
int sample_counter = 0;
uint8_t sample = 0;
//If we want to do averaging
uint32_t sample_sum =0 ;
uint32_t sample_total_numbers =0 ;
uint32_t sample_total_saved =0 ;
while(!BUTTON_PRESS() && !usb_poll_validate_length() ) {
WDT_HIT();
if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
AT91C_BASE_SSC->SSC_THR = 0x43;
LED_D_ON();
}
if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
sample = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
LED_D_OFF();
// threshold either high or low values 128 = center 0. if trigger = 178
if ((trigger_threshold > 0) && (sample < (trigger_threshold+128)) && (sample > (128-trigger_threshold))) //
continue;
trigger_threshold = 0;
sample_total_numbers++;
if(averaging)
{
sample_sum += sample;
}
//Check decimation
if(decimation > 1)
{
sample_counter++;
if(sample_counter < decimation) continue;
sample_counter = 0;
}
//Averaging
if(averaging && decimation > 1) {
sample = sample_sum / decimation;
sample_sum =0;
}
//Store the sample
sample_total_saved ++;
if(bits_per_sample == 8){
dest[sample_total_saved-1] = sample;
data.numbits = sample_total_saved << 3;//Get the return value correct
if(sample_total_saved >= bufsize) break;
}
else{
pushBit(&data, sample & 0x80);
if(bits_per_sample > 1) pushBit(&data, sample & 0x40);
if(bits_per_sample > 2) pushBit(&data, sample & 0x20);
if(bits_per_sample > 3) pushBit(&data, sample & 0x10);
if(bits_per_sample > 4) pushBit(&data, sample & 0x08);
if(bits_per_sample > 5) pushBit(&data, sample & 0x04);
if(bits_per_sample > 6) pushBit(&data, sample & 0x02);
//Not needed, 8bps is covered above
//if(bits_per_sample > 7) pushBit(&data, sample & 0x01);
if((data.numbits >> 3) +1 >= bufsize) break;
}
}
}
int DemodPCF7931(uint8_t **outBlocks) {
uint8_t bits[256] = {0x00};
uint8_t blocks[8][16];
uint8_t *dest = BigBuf_get_addr();
int GraphTraceLen = BigBuf_max_traceLen();
if ( GraphTraceLen > 18000 )
GraphTraceLen = 18000;
int i, j, lastval, bitidx, half_switch;
int clock = 64;
int tolerance = clock / 8;
int pmc, block_done;
int lc, warnings = 0;
int num_blocks = 0;
int lmin=128, lmax=128;
uint8_t dir;
//clear read buffer
BigBuf_Clear_keep_EM();
LFSetupFPGAForADC(95, true);
DoAcquisition_default(0, true);
lmin = 64;
lmax = 192;
i = 2;
/* Find first local max/min */
if(dest[1] > dest[0]) {
while(i < GraphTraceLen) {
if( !(dest[i] > dest[i-1]) && dest[i] > lmax)
break;
i++;
}
dir = 0;
}
else {
while(i < GraphTraceLen) {
if( !(dest[i] < dest[i-1]) && dest[i] < lmin)
break;
i++;
}
dir = 1;
}
lastval = i++;
half_switch = 0;
pmc = 0;
block_done = 0;
for (bitidx = 0; i < GraphTraceLen; i++)
{
if ( (dest[i-1] > dest[i] && dir == 1 && dest[i] > lmax) || (dest[i-1] < dest[i] && dir == 0 && dest[i] < lmin))
{
lc = i - lastval;
lastval = i;
// Switch depending on lc length:
// Tolerance is 1/8 of clock rate (arbitrary)
if (ABS(lc-clock/4) < tolerance) {
// 16T0
if((i - pmc) == lc) { /* 16T0 was previous one */
/* It's a PMC ! */
i += (128+127+16+32+33+16)-1;
lastval = i;
pmc = 0;
block_done = 1;
}
else {
pmc = i;
}
} else if (ABS(lc-clock/2) < tolerance) {
// 32TO
if((i - pmc) == lc) { /* 16T0 was previous one */
/* It's a PMC ! */
i += (128+127+16+32+33)-1;
lastval = i;
pmc = 0;
block_done = 1;
}
else if(half_switch == 1) {
bits[bitidx++] = 0;
half_switch = 0;
}
else
half_switch++;
} else if (ABS(lc-clock) < tolerance) {
// 64TO
bits[bitidx++] = 1;
} else {
// Error
warnings++;
if (warnings > 10)
{
Dbprintf("Error: too many detection errors, aborting.");
return 0;
}
}
if(block_done == 1) {
if(bitidx == 128) {
for(j=0; j<16; j++) {
blocks[num_blocks][j] = 128*bits[j*8+7]+
64*bits[j*8+6]+
32*bits[j*8+5]+
16*bits[j*8+4]+
8*bits[j*8+3]+
4*bits[j*8+2]+
2*bits[j*8+1]+
bits[j*8];
}
num_blocks++;
}
bitidx = 0;
block_done = 0;
half_switch = 0;
}
if(i < GraphTraceLen)
dir =(dest[i-1] > dest[i]) ? 0 : 1;
}
if(bitidx==255)
bitidx=0;
warnings = 0;
if(num_blocks == 4) break;
}
memcpy(outBlocks, blocks, 16*num_blocks);
return num_blocks;
}